1. Field of the Invention
The present invention relates to a recording apparatus of a master disk of optical discs, which adjusts a position where a recording beam is irradiated onto the master disc.
2. Description of Related Art
As a recording apparatus of a master disc of optical discs for recording a recording signal by irradiating a recording beam onto the master disc, an apparatus disclosed in Japanese Patent Kokai No. 6-131706 is known. In the apparatus mentioned above, a master disc of optical discs held by a rotary shaft of a spindle motor is rotated by the spindle motor, and a recording beam, for example, an electron beam is irradiated onto the master disc. A recording signal is recorded onto a recording surface of the master disc in this way.
As mentioned above, to record a recording signal, the master disc of optical discs is rotated by rotating the spindle motor, thereby to perform recording. However, if vibrations caused by the rotating motion of the spindle motor are propagated to the master disc, or a rotation fluctuation occurs in the spindle motor, then a problem can arise that a laser beam may not be irradiated onto a proper position on the master disc.
The invention was made in view of the foregoing problem, and it is an object of the invention to provide a recording apparatus of a master disc of optical discs, which can irradiate a recording beam to a preferable position on the master disc of optical discs.
According to the invention, there is provided a recording apparatus of a master disc of optical discs comprising: rotation driving means for rotating a rotary shaft to rotate a master disc; angle position detecting means for detecting an angle position in the rotating direction of the rotary shaft and generating an angle position signal; irradiating means for irradiating a recording beam to the master disc based on an information recording signal; and irradiating position control means for controlling an irradiating spot position of the recording beam on the master disc, wherein the irradiating position control means comprises displacement detecting means for detecting a displacement of the rotary shaft in the radial direction of the master disc and generating a displacement detection signal, deviation calculating means for calculating a present deviation at a present angle position from a reference position of the rotary shaft based on the angle position signal and the displacement detection signal, and irradiating position adjusting means for adjusting the irradiating spot position based on the present deviation.
According to one aspect of the invention, even when the vibration occurs in the rotary shaft, the recording beam can be irradiated on the preferable position on the master disc since the irradiating spot position is adjusted based on the present deviation.
According to another aspect of the invention, even when the rotation fluctuation occurs in the spindle motor, the recording beam can be irradiated on the preferable position on the master disc since the irradiating spot position is adjusted based on a present deviation phase difference.